1. Field of the Invention
Methods and systems consistent with the present invention relate to supporting a space time block code (STBC) scheme and more particularly, to an equalization gain in a single carrier (SC) system based on a unique word (UW) which can acquire diversity gain, and can achieve enhanced performance without error propagation.
2. Description of Related Art
With increased demand for data transmission using a wireless communication system by users, services such as the third generation (3G) mobile communications are provided, and various research, enabling the users to more effectively perform data transmission of high speed and high quality, are briskly under way. Particularly, introduction of a multiple input multiple output (MIMO) system is necessary instead of a conventional single transmission/reception antenna since a substantially high capacity channel is required in next generation mobile communication systems, demanding high speed and high quality data transmission. The MIMO system indicates a multi-antenna system having multiple inputs and multiple outputs.
Particularly, research with respect increased reliability of transmission information of a transmitter and a receiver, is briskly under way. The transmitter and the receiver can acquire a diversity gain for the transmitted information by using an STBC scheme, i.e. a closed loop method which is not required to feedback channel information to a transmitter, and can increase volume of information by transmitting different information for each transmission antenna in the MIMO system.
Also, when a channel quickly changes in a high speed mobile environment, various types of distortions may occur while the transmitted signals pass through a transmission channel. There are various reasons for causing the various distortions, such as a power change of a received signal due to a fading phenomenon, and an interference due to other users, multi-path signals, a gaussain noise, an impulse noise, and a white noise. With respect to a channel equalization technology to reduce a bit detection error by correcting distortions occurring due to a poor quality transmission channel, an effort to enhance an equalization performance is under way for high speed and high quality data transmission.
However, a transmitter and a receiver supporting an STBC scheme in an SC system based on a cyclic prefix (CP) according to a conventional art have problems in that error propagation may occur due to a frequency domain-decision feedback equalization (FD-DFE), and it is difficult to use a pilot symbol for channel estimation and synchronization.
Therefore, a transmitter, a receiver, and a method which can acquire both a diversity gain and an equalization gain in a SC system based on a unique word (UW), and can achieve an enhanced performance without an error propagation is needed.